Hi babar,

If you find difficulties in sourcing the chip what steve is suggeting, you can also use ULN2003. It is widely available in Pakistan.

All rows can be parallel connected, and columns can be arranged at the set of 8 I/O lines. you can use 74LS374 or 74Ls373 as the latch and can consider them external RAM, called memory mapped I/O. Consider every 8 i/o lines as an external memory location and try to write on that. You will require address decoding, such as 74LS138 or 74LS139 to distinguish between which latch to be addressed.

This is very interesting and easy project. You can bring sophistication in it by interfacing PC keyboard for input, bultin software RTC, double width characters, and different graphics pattern to be displayed. Also keep in mind that there are high-lumins LEDs are available for use in day-light. And blue LEDs are also available, you must be knowing about this.

Baber, this is very interesting field, and can make good money if developed in professional manner.

A week back, I got a quotation from a Taiwanese LED matrixed bill board manufacturer, you know how much for a 3mx4m bill board is, not less then US$300,000.

I have studied this in detail when I was in university, and we had craze about "Moving message".

Ha.. ha.. ha.. Again Zilog.....
At zilog site there is an example code for such display. You can try at www.zilog.com

goodluck..

Rauf